Mitochondrial Dysfunction in Parkinson's Disease

Genetic risk for neurodegenerative conditions is linked to disease-specific microglial pathways

Genome-wide association studies have identified thousands of common variants associated with an increased risk of neurodegenerative disorders. However, the noncoding localization of these variants has made the assignment of target genes for brain cell types challenging. Genomic approaches that infer chromosomal 3D architecture can link noncoding risk variants and distal gene regulatory elements such as enhancers to gene promoters. By using enhancer-to-promoter interactome maps for human microglia, neurons, and oligodendrocytes, we identified cell-type-specific enrichment of genetic heritability for brain disorders through stratified linkage disequilibrium score regression. Our analysis suggests that genetic heritability for multiple neurodegenerative disorders is enriched at microglial chromatin contact sites, while schizophrenia heritability is predominantly enriched at chromatin contact sites in neurons followed by oligodendrocytes. Through Hi-C coupled multimarker analysis of genomic annotation (H-MAGMA), we identified disease risk genes for Alzheimer's disease, Parkinson's disease, multiple sclerosis, amyotrophic lateral sclerosis and schizophrenia. We found that disease-risk genes were overrepresented in microglia compared to other brain cell types across neurodegenerative conditions and within neurons for schizophrenia. Notably, the microglial risk genes and pathways identified were largely specific to each disease. Our findings reinforce microglia as an important, genetically informed cell type for therapeutic interventions in neurodegenerative conditions and highlight potentially targetable disease-relevant pathways.

Immune cell metabolic dysfunction in Parkinson's disease

Parkinson's disease (PD) is a multi-system disorder characterized histopathologically by degeneration of dopaminergic neurons in the substantia nigra pars compacta. While the etiology of PD remains multifactorial and complex, growing evidence suggests that cellular metabolic dysfunction is a critical driver of neuronal death. Defects in cellular metabolism related to energy production, oxidative stress, metabolic organelle health, and protein homeostasis have been reported in both neurons and immune cells in PD. We propose that these factors act synergistically in immune cells to drive aberrant inflammation in both the CNS and the periphery in PD, contributing to a hostile inflammatory environment which renders certain subsets of neurons vulnerable to degeneration. This review highlights the overlap between established neuronal metabolic deficits in PD with emerging findings in central and peripheral immune cells. By discussing the rapidly expanding literature on immunometabolic dysfunction in PD, we aim to draw attention to potential biomarkers and facilitate future development of immunomodulatory strategies to prevent or delay the progression of PD.

Investigating cuproptosis and mitochondrial dysfunction in brain cells: uncovering novel mechanisms and biomarkers for Parkinson's disease

Parkinson's disease (PD) is a chronic neurodegenerative condition marked by the gradual degeneration of dopaminergic neurons, resulting in a range of disabling motor and non-motor symptoms. Despite advances, the molecular mechanisms underlying PD remain elusive, and effective biomarkers and therapeutic targets are limited. Recent studies suggest that mitochondrial dysfunction and dysregulated cellular metabolism are central to PD pathogenesis. This study investigated cuproptosis-related genes (CRGs), a class of genes linked to mitochondrial function and metabolic pathways, as potential contributors to PD using in silico and in vitro analyses. By analyzing Gene Expression Omnibus (GEO) datasets, we identified a consistent downregulation of CRGs, including DLD, FDX1, LIPT1, LIAS, PDHB, DLAT, PDHA1, CDKN2A, MTF1, and GLS, in PD samples. Immune infiltration analysis and subcellular localization studies highlighted significant correlations with immune cells and mitochondrial localization, implicating CRGs in immune and metabolic dysregulation. Functional assays confirmed that overexpression of DLD and FDX1 promotes cell proliferation and migration, suggesting their involvement in PD progression. Diagnostic model analysis further demonstrated the strong potential of CRGs as biomarkers, with high Area Under the Curve (AUC) values indicating accuracy in distinguishing PD from controls. Additionally, miRNA-mRNA interaction and drug sensitivity analyses identified key regulatory microRNAs (miRNAs) and drug sensitivities associated with CRGs expression. Pathway enrichment analysis linked CRGs to essential mitochondrial and metabolic processes, providing insights into PD's underlying mechanisms. The findings of this study emphasize the diagnostic and therapeutic potential of CRGs in PD, offering a novel avenue for understanding and managing this complex disease.

Intranasal administration of mesenchymal stem cells overexpressing FGF21 demonstrates therapeutic potential in experimental Parkinson's disease

Parkinson's disease (PD) is a prevalent movement disorder characterized by mitochondrial dysfunction and dopaminergic neuronal loss in the substantia nigra of the midbrain. Currently, there are no effective treatments to cure or slow the progression of PD, highlighting an urgent need for new therapeutic strategies. Emerging evidence suggests that mesenchymal stem cells (MSCs) and fibroblast growth factor 21 (FGF21) are potential candidates for PD treatment. This study investigates a therapeutic strategy involving FGF21 delivered via mouse MSCs in the PD model of mice treated with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) and dopaminergic SH-SY5Y cells exposed to 1-methyl-4-phenylpyridinium (MPP+). FGF21-overexpressing MSCs were administered intranasally, either before or after MPTP treatment in mice. Intranasally delivered FGF21-overexpressing MSCs efficiently migrated to the injured substantia nigra, ameliorated MPTP-induced PD-like motor deficits, reinstated dopaminergic neurons in the substantia nigra and nerve terminals in the striatum, as well as normalized brain-derived neurotrophic factor (BDNF) and FGF21 levels. In contrast, MSCs not overexpressing FGF21 showed limited or no impact on these parameters. In a PD cellular model of MPP+-treated SH-SY5Y cells, FGF21-overexpressing MSCs showed enhanced PD cell viability. Treatment with conditioned medium from FGF21-overexpressing MSCs or exogenous FGF21 prevented cell death, reduced mitochondrial reactive oxygen species (ROS), and restored neuroprotective proteins, including phospho-Akt, BDNF, and Bcl-2. These findings indicate that intranasal delivery of FGF21-overexpressing MSCs holds promise as a potential PD therapy, likely through activating the Akt-BDNF-Bcl-2 pathway, normalizing mitochondrial dysfunction, and mitigating dopaminergic neurodegeneration. Further clinical investigations are essential to validate these promising findings.

Targeting the ClpP-αSynuclein Interaction with a Decoy Peptide to Mitigate Neuropathology in Parkinson's Disease Models

Parkinson's disease (PD), the most prevalent neurodegenerative movement disorder, is characterized by the progressive loss of dopaminergic (DA) neurons and the accumulation of α-synuclein (αSyn)-rich inclusions. Despite advances in understanding PD pathophysiology, disease-modifying therapies remain elusive, underscoring gaps in our knowledge of its underlying mechanisms. Mitochondria are key targets of αSyn toxicity, and growing evidence suggests that αSyn-mitochondrial interactions contribute to PD progression. Our recent findings identify mitochondrial protease ClpP as a crucial regulator of αSyn pathology, with pathological αSyn binding to and impairing ClpP function, thereby exacerbating mitochondrial impairment and neurodegeneration. To disrupt this deleterious interaction, we developed a decoy peptide, CS2, which directly binds to the non-amyloid-β component (NAC) domain of αSyn, preventing its association with ClpP. CS2 treatment effectively mitigated αSyn toxicity in an αSyn-stable neuronal cell line, primary cortical neurons inoculated with αSyn pre-formed fibrils (PFFs), and DA neurons derived from PD patient-induced pluripotent stem cells (iPSCs). Notably, subcutaneous administration of CS2 in transgenic mThy1-hSNCA PD mice rescued cognitive and motor deficits while reducing αSyn aggregation and neuropathology. These findings establish the ClpP-αSyn interaction as a druggable target in PD and position CS2 as a promising therapeutic candidate for PD and other αSyn-associated neurodegenerative disorders.

Mitochondrial dysfunction, iron accumulation, lipid peroxidation, and inflammasome activation in cellular models derived from patients with multiple sclerosis

Multiple sclerosis (MS) is an inflammatory demyelinating disease of the central nervous system (CNS). Despite advancements in managing relapsing active illness, effective treatments for the irreversible progressive decline in MS remain limited. Research employing skin fibroblasts obtained from patients with neurological disorders revealed modifications in cellular stress pathways and bioenergetics. However, research using MS patient-derived cellular models is scarce. In this study, we collected fibroblasts from two MS patients to investigate cellular pathological alterations. We observed that MS fibroblasts showed a senescent morphology associated with iron/lipofuscin accumulation and altered expression of iron metabolism proteins. In addition, we found increased lipid peroxidation and downregulation of antioxidant enzymes expression levels in MS fibroblasts. When challenged against erastin, a ferroptosis inducer, MS fibroblasts showed decreased viability, suggesting increased sensitivity to ferroptosis. Furthermore, MS fibroblasts presented alterations in the expression levels of autophagy-related proteins. Interestingly, these alterations were associated with mitochondrial dysfunction and inflammasome activation. These findings were validated in 7 additional patient-derived cell lines. Our findings suggest that the underlying stress phenotype of MS fibroblasts may be disease-specific and recapitulate the main cellular pathological alterations found in the disease such as mitochondrial dysfunction, iron accumulation, lipid peroxidation, inflammasome activation, and pro-inflammatory cytokine production.

Free radicals and their impact on health and antioxidant defenses: a review

Free radicals, characterized by the presence of unpaired electrons, are highly reactive species that play a significant role in human health. These molecules can be generated through various endogenous processes, such as mitochondrial respiration and immune cell activation, as well as exogenous sources, including radiation, pollution, and smoking. While free radicals are essential for certain physiological processes, such as cell signaling and immune defense, their overproduction can disrupt the delicate balance between oxidants and antioxidants, leading to oxidative stress. Oxidative stress results in the damage of critical biomolecules like DNA, proteins, and lipids, contributing to the pathogenesis of various diseases. Chronic conditions such as cancer, cardiovascular diseases, neurodegenerative disorders, and inflammatory diseases have been strongly associated with the harmful effects of free radicals. This review provides a comprehensive overview of the characteristics and types of free radicals, their mechanisms of formation, and biological impacts. Additionally, we explore natural compounds and extracts studied for their antioxidant properties, offering potential therapeutic avenues for managing free radical-induced damage. Future research directions are also discussed to advance our understanding and treatment of free radical-associated diseases.

Nitric Oxide in Parkinson's Disease: The Potential Role of Dietary Nitrate in Enhancing Cognitive and Motor Health via the Nitrate-Nitrite-Nitric Oxide Pathway

BACKGROUND/OBJECTIVES

Parkinson's disease (PD) is a progressive neurodegenerative disorder characterized by the loss of dopaminergic neurons in the substantia nigra pars compacta, leading to motor symptoms such as tremor, rigidity, and bradykinesia. The pathological hallmarks of PD include Lewy bodies and mechanisms like oxidative/nitrosative stress, chronic inflammation, and mitochondrial dysfunction. Nitric oxide (NO), produced by nitric oxide synthase (NOS) isoforms, plays a dual role in neuroprotection and neurodegeneration. Excessive NO production exacerbates neuroinflammation and oxidative/nitrosative damage, contributing to dopaminergic cell death. This review explores NO's role in PD pathogenesis and investigates dietary nitrate as a therapeutic strategy to regulate NO levels.

METHODS

A literature review of studies addressing the role of NO in PD was conducted using major scientific databases, including PubMed, Scopus, and Web of Science, using keywords such as "nitric oxide", "NOSs", "Parkinson's disease", and "nitrate neuroprotection in PD". Studies on nitrate metabolism via the nitrate-nitrite-NO pathway and its effects on PD hallmarks were analyzed. Studies regarding the role of nitrosamine formation in PD, which are mainly formed during the nitrification process of amines (nitrogen-containing compounds), often due to chemical reactions in the presence of nitrite or nitrate, were also examined. In particular, nitrate has been shown to induce oxidative stress, affect the mitochondrial function, and contribute to inflammatory phenomena in the brain, another factor closely related to the pathogenesis of PD.

RESULTS

Excessive NO production, particularly from iNOS and nNOS, was strongly associated with neuroinflammation and oxidative/nitrosative stress, amplifying neuronal damage in PD. Dietary nitrate was shown to enhance NO bioavailability through the nitrate-nitrite-NO pathway, mitigating inflammation and oxidative/nitrosative damage.

CONCLUSIONS

Dysregulated NO production contributes significantly to PD progression via inflammatory and oxidative/nitrosative pathways. Dietary nitrate, by modulating NO levels, offers a promising therapeutic strategy to counteract these pathological mechanisms. Further clinical trials are warranted to establish its efficacy and optimize its use in PD management.

Evolving Landscape of Parkinson's Disease Research: Challenges and Perspectives

Parkinson's disease (PD) is a progressive neurodegenerative disorder that primarily affects movement. It occurs due to a gradual deficit of dopamine-producing brain cells, particularly in the substantia nigra. The precise etiology of PD is not fully understood, but it likely involves a combination of genetic and environmental factors. The therapies available at present alleviate symptoms but do not stop the disease's advancement. Research endeavors are currently directed at inventing disease-controlling therapies that aim at the inherent mechanisms of PD. PD biomarker breakthroughs hold enormous potential: earlier diagnosis, better monitoring, and targeted treatment based on individual response could significantly improve patient outcomes and ease the burden of this disease. PD research is an active and evolving field, focusing on understanding disease mechanisms, identifying biomarkers, developing new treatments, and improving care. In this report, we explore data from the CAS Content Collection to outline the research progress in PD. We analyze the publication landscape to offer perspective into the latest expertise advancements. Key emerging concepts are reviewed and strategies to fight disease evaluated. Pharmacological targets, genetic risk factors, as well as comorbid diseases are explored, and clinical usage of products against PD with their production pipelines and trials for drug repurposing are examined. This review aims to offer a comprehensive overview of the advancing landscape of the current understanding about PD, to define challenges, and to assess growth prospects to stimulate efforts in battling the disease.

Space exploration and risk of Parkinson's disease: a perspective review

Systemic mitochondrial dysfunction, dopamine loss, sustained structural changes in the basal ganglia including reduced tyrosine hydroxylase, and altered gait- these effects observed in space-flown animals and astronauts mirrors Parkinson's disease (PD). Evidence of mitochondrial changes in space-flown human cells, examined through the lens of PD, suggests that spaceflight-induced PD-like molecular changes are important to monitor during deep space exploration. These changes, may potentially elevate the risk of PD in astronauts.

Pyrroloquinoline quinone: a potential neuroprotective compound for neurodegenerative diseases targeting metabolism

Pyrroloquinoline quinone is a quinone described as a cofactor for many bacterial dehydrogenases and is reported to exert an effect on metabolism in mammalian cells/tissues. Pyrroloquinoline quinone is present in the diet being available in foodstuffs, conferring the potential of this compound to be supplemented by dietary administration. Pyrroloquinoline quinone's nutritional role in mammalian health is supported by the extensive deficits in reproduction, growth, and immunity resulting from the dietary absence of pyrroloquinoline quinone, and as such, pyrroloquinoline quinone has been considered as a "new vitamin." Although the classification of pyrroloquinoline quinone as a vitamin needs to be properly established, the wide range of benefits for health provided has been reported in many studies. In this respect, pyrroloquinoline quinone seems to be particularly involved in regulating cell signaling pathways that promote metabolic and mitochondrial processes in many experimental contexts, thus dictating the rationale to consider pyrroloquinoline quinone as a vital compound for mammalian life. Through the regulation of different metabolic mechanisms, pyrroloquinoline quinone may improve clinical deficits where dysfunctional metabolism and mitochondrial activity contribute to induce cell damage and death. Pyrroloquinoline quinone has been demonstrated to have neuroprotective properties in different experimental models of neurodegeneration, although the link between pyrroloquinoline quinone-promoted metabolism and improved neuronal viability in some of such contexts is still to be fully elucidated. Here, we review the general properties of pyrroloquinoline quinone and its capacity to modulate metabolic and mitochondrial mechanisms in physiological contexts. In addition, we analyze the neuroprotective properties of pyrroloquinoline quinone in different neurodegenerative conditions and consider future perspectives for pyrroloquinoline quinone's potential in health and disease.

Involvement of Autophagic Machinery in Neuropathogenesis: Targeting and Relevant Methods of Detection

The exquisite balance between cellular prosurvival and death pathways is extremely necessary for homeostasis. Different forms of programmed cell death have been widely studied and reported such as apoptosis, necroptosis, pyroptosis, and autophagy. Autophagy is a catabolic process important for normal cellular functioning. The main aim of this machinery is to degrade the misfolded or damaged proteins, unuseful organelles, and pathogens, which invade the cells, thereby maintaining cellular homeostasis and assuring the regular renewal of cell components. This prosurvival function of autophagy highlights its importance in many human diseases, as the disturbance of this tightly organized process ultimately causes detrimental effects. Interestingly, neurons are particularly susceptible to damage upon the presence of any alteration in the basal level of the autophagic activity; this could be due to their high metabolic demand, post-mitotic nature, and the contribution of autophagy in the different fundamental functions of neurons. Herein, we have reported the role of autophagy in different CNS disorders such as Parkinson's disease, Alzheimer's disease, Huntington's disease, and epilepsy, besides the pharmacological agents targeting autophagy. Due to the significant contribution of autophagy in the pathogenesis of many diseases, it is crucial to develop effective methods to detect this dynamic process. In this chapter, we have summarized the most frequently employed techniques in studying and detecting autophagy including electron microscopy, fluorescence microscopy, Western blotting, intracellular protein degradation, and sequestration assay.

AdipoRon improves mitochondrial homeostasis and protects dopaminergic neurons through activation of the AMPK signaling pathway in the 6-OHDA-lesioned rats

The progressive decline of dopaminergic neurons in Parkinson's disease (PD) has been linked to an imbalance in energy and the failure of mitochondrial function. AMP-activated protein kinase (AMPK), the major intracellular energy sensor, regulates energy balance, and damage to nigral dopaminergic neurons induced by 6-hydroxydopamine (6-OHDA) is exacerbated in the absence of AMPK activity. This study aimed to examine the potential therapeutic advantages of AdipoRon, an AMPK activator, on motor function and mitochondrial homeostasis in a 6-OHDA-induced PD model. Male Wistar rats were subjected to unilateral injection of 6-OHDA (10 μg) into the left medial forebrain bundle at two points, and after 7 days, they were treated with intranasal AdipoRon (0.1, 1, and 10 μg) or Levodopa (10 mg/kg, p. o.) for 21 successive days. Following the last treatment day, motor behavior was evaluated through the Murprogo's test, bar test, beam walking test, and apomorphine-induced rotation test. After euthanasia, the left substantia nigra (SN) was separated for evaluation of ATP, mitochondrial membrane potential (MMP), and protein expressions of AMPK, p-AMPK, and mitochondrial dynamics markers (Mfn-2 and Drp-1). Moreover, the number of tyrosine hydroxylase-positive (TH+) cells was quantified in the left substantia nigra. Intranasal AdipoRon effectively reversed muscle rigidity, akinesia, bradykinesia, and rotation caused by 6-OHDA. Moreover, AdipoRon increased the phospho-AMPK/AMPK ratio, mitigated mitochondrial dysfunction, and improved mitochondrial dynamics in the SN. Furthermore, AdipoRon increased the number of TH+ cells in the SN of PD animals. These findings suggest that AdipoRon could protect dopaminergic neurons by activating the AMPK pathway and improving mitochondrial dysfunction.

Peripheral immune cell response to stimulation stratifies Parkinson's disease progression from prodromal to clinical stages

The motor stage of idiopathic Parkinson's disease (iPD) can be preceded for years by a prodromal stage characterized by non-motor symptoms like REM sleep behavior disorder (RBD). Here, we show that multiple stages of iPD, including the pre-motor prodromal stage, can be stratified according to the inflammatory and immunometabolic responses to stimulation of peripheral blood mononuclear cells ex vivo. We identified increased stimulation-dependent secretion of TNF, IL-1β, and IL-8 in monocytes from RBD patients and showed diminished proinflammatory cytokine secretion in monocytes and T cells in early and moderate stages of PD. Mechanistically, immune activation revealed deficits in CD8+ T-cell mitochondrial health in moderate PD, and relative mitochondrial health in CD8+ T cells was positively correlated with stimulation-dependent T-cell cytokine secretion across the PD spectrum. Dysregulated immunometabolism may drive peripheral inflammation and PD progression, and ex vivo stimulation-based assays have potential to reveal novel biomarkers for patient stratification and progression with immune endophenotypes.

Robust In Vitro Models for Studying Parkinson's Disease? LUHMES Cells and SH-SH5Y Cells

As our population ages, there is an increased unmet clinical need surrounding neurodegenerative diseases such as Parkinson's disease (PD). To tackle this ever-increasing problem, we must ensure that the cell models that we use to develop therapeutics in vitro are robust, reliable, and replicable. In this study, we compared SH-SY5Y cells with LUHMES cells in response to 6-Hydroxydopamine (6OHDA) and 1-Methyl-4-phenylpyridinium (MPP+), two common Parkinson's insults used in in vitro analysis. Both these cell types have apparent dopaminergic phenotypes, which could aid us in understanding their potential in this race to novel therapies. The LUHMES cells showed consistent dopaminergic (DA) expression through tyrosine hydroxylase (TH) positivity, alongside depleted ATP levels and elevated reactive oxygen species (ROS) production, whereas the SH-SH5Y cells displayed resilience to both chemical insults, raising questions about their utility in accurately modelling PD pathology. Further electrophysiological analysis revealed comparable firing rates and ion channel signalling between both cell types; however, LUHMES cells demonstrated stronger calcium signalling responses, further supporting their use as a more robust PD model. While SH-SY5Y cells showed some adaptability in vitro, their inconsistent DA phenotype and limited response to chemical insults limit their suitability for advanced research, suggesting that LUHMES cells should and must take their place as a hallmark in Parkinson's disease research.

SUMOylation modulates mitochondrial dynamics in an in vitro rotenone model of Parkinson's disease

SUMOylation is a post-translational modification essential for various biological processes. SUMO proteins bind to target substrates in a three-step enzymatic pathway, which is rapidly reversible by the action of specific proteases, known as SENPs. Studies have shown that SUMOylation is dysregulated in several human disorders, including neurodegenerative diseases that are characterized by the progressive loss of neurons, mitochondrial dysfunction, deficits in autophagy, and oxidative stress. Considering the potential neuroprotective roles of SUMOylation, the aim of this study was to investigate the effects of SENP3 knockdown in H4 neuroglioma cells exposed to rotenone, an in vitro model of cytotoxicity that mimics dopaminergic loss in Parkinson's disease (PD). The current data show that SENP3 knockdown increases SUMO-2/3 conjugates, which is accompanied by reduced levels of the mitochondrial fission protein Drp1 and increased levels of the mitochondrial fusion protein OPA1. Of high interest, SENP3 knockdown prevented rotenone-induced superoxide production and cellular death. Taken together, these findings highlight the importance of SUMOylation in maintaining mitochondrial homeostasis and the neuroprotective potential of this modification in PD.

In vitro modelling of Parkinson's disease using 6-OHDA is associated with increased NQO2 activity

The pathogenesis of Parkinson's disease (PD) involves abnormalities in the metabolism of catecholamines. The enzyme quinone reductase 2 (NQO2) reduces quinone derivatives of catecholamines, which promotes the formation of reactive oxygen species (ROS), suggesting a role for NQO2 in the development of cellular damage typical of PD. In the present study, we investigated the relationship between 6-hydroxydophamine (6-OHDA) induced cellular damage and NQO2 activity and its levels in SH-SY5Y cell culture to establish an experimental model to evaluate the pharmacological properties of NQO2 inhibitors. Cellular damage was evaluated using the MTT and comet assays. It was shown that oxidative damage of SH-SY5Y cells upon incubation with 6-OHDA for 6, 12 and 24 h was accompanied by an increase in NQO2 activity. The increase in NQO2 protein level in SH-SY5Y cells was observed 24 h after incubation with 6-OHDA at concentrations of 50 and 100 μM. Oxidative damage of SH-SY5Y cells upon 1 h incubation with 6-OHDA is increased in the presence of the selective enzyme co-substrate 1-benzyl-1,4-dihydronicotinamide (BNAH), but is not accompanied by changes in NQO2 activity and protein levels. The data obtained demonstrate the contribution of NQO2 to the cytotoxic mechanism of 6-OHDA action.

Decoding Neurodegeneration: A Review of Molecular Mechanisms and Therapeutic Advances in Alzheimer's, Parkinson's, and ALS

Neurodegenerative diseases, such as Alzheimer's, Parkinson's, ALS, and Huntington's, remain formidable challenges in medicine, with their relentless progression and limited therapeutic options. These diseases arise from a web of molecular disturbances-misfolded proteins, chronic neuroinflammation, mitochondrial dysfunction, and genetic mutations-that slowly dismantle neuronal integrity. Yet, recent scientific breakthroughs are opening new paths to intervene in these once-intractable conditions. This review synthesizes the latest insights into the underlying molecular dynamics of neurodegeneration, revealing how intertwined pathways drive the course of these diseases. With an eye on the most promising advances, we explore innovative therapies emerging from cutting-edge research: nanotechnology-based drug delivery systems capable of navigating the blood-brain barrier, gene-editing tools like CRISPR designed to correct harmful genetic variants, and stem cell strategies that not only replace lost neurons but foster neuroprotective environments. Pharmacogenomics is reshaping treatment personalization, enabling tailored therapies that align with individual genetic profiles, while molecular diagnostics and biomarkers are ushering in an era of early, precise disease detection. Furthermore, novel perspectives on the gut-brain axis are sparking interest as mounting evidence suggests that microbiome modulation may play a role in reducing neuroinflammatory responses linked to neurodegenerative progression. Taken together, these advances signal a shift toward a comprehensive, personalized approach that could transform neurodegenerative care. By integrating molecular insights and innovative therapeutic techniques, this review offers a forward-looking perspective on a future where treatments aim not just to manage symptoms but to fundamentally alter disease progression, presenting renewed hope for improved patient outcomes.

Magnesium (Mg) and Neurodegeneration: A Comprehensive Overview of Studies on Mg Levels in Biological Specimens in Humans Affected Some Neurodegenerative Disorders with an Update on Therapy and Clinical Trials Supplemented with Selected Animal Studies

Neurodegenerative diseases, characterized by neuron loss, are a group of neurological disorders that adversely affect the lives of millions of people worldwide. Although several medicines have been approved for managing neurodegenerative diseases, new therapies allowing for a significant slowdown in the progression of neurodegenerative syndromes are constantly being sought. Magnesium (Mg), a crucial mineral necessary for the functioning of organisms, is important to normal central nervous system (CNS) activity. Although the effects of this bioelement on the CNS are relatively well recognized, its role in the pathophysiology of neurological disorders in humans is not yet well characterized. Therefore, the main goal of this review is to collect data about a possible association between Mg and neurodegenerative disorders such as Alzheimer's disease (AD), Parkinson's Disease (PD), and Amyotrophic lateral sclerosis (ALS) in humans. Hence, the levels of Mg in blood, cerebrospinal fluid (CSF), urine, and hair from subjects with AD, PD, and ALS are compiled to detect possible variations in the levels of this mineral in the biological specimens of people with neurodegenerative illnesses. Additionally, the findings from an animal model are summarized to offer the reader a deeper insight into studies on Mg in the context of neuroprotection and neurodegeneration. Data provided in the present review indicate that Mg, due to its neuroprotective, antioxidant, anti-inflammatory, and mitochondrial-supportive properties, could be a potential therapeutic agent for AD, PD, and ALS. However, more epidemiological studies with standardized methods of dietary assessment and Mg measurement are necessary to recognize its exact role in neurodegenerative disorders. Moreover, extensive well-designed clinical trials are also needed to establish definitive therapeutic protocols and optimal dosages, and to ensure long-term safety of this mineral supplementation in AD, PD, and ALS patients.

Nrf2 pathways in neuroprotection: Alleviating mitochondrial dysfunction and cognitive impairment in aging

Mitochondrial dysfunction and cognitive impairment are widespread phenomena among the elderly, being crucial factors that contribute to neurodegenerative diseases. Nuclear factor erythroid 2-related factor 2 (Nrf2) is an important regulator of cellular defense systems, including that against oxidative stress. As such, increased Nrf2 activity may serve as a strategy to avert mitochondrial dysfunction and cognitive decline. Scientific data on Nrf2-mediated neuroprotection was collected from PubMed, Google Scholar, and Science Direct, specifically addressing mitochondrial dysfunction and cognitive impairment in older people. Search terms included "Nrf2", "mitochondrial dysfunction," "cognitive impairment," and "neuroprotection." Studies focusing on in vitro and in vivo models and clinical investigations were included to review Nrf2's therapeutic potential comprehensively. The relative studies have demonstrated that increased Nrf2 activity could improve mitochondrial performance, decrease oxidative pressure, and mitigate cognitive impairment. To a large extent, this is achieved through the modulation of critical cellular signalling pathways such as the Keap1/Nrf2 pathway, mitochondrial biogenesis, and neuroinflammatory responses. The present review summarizes the recent progress in comprehending the molecular mechanisms regarding the neuroprotective benefits mediated by Nrf2 through its substantial role against mitochondrial dysfunction and cognitive impairment. This review also emphasizes Nrf2-target pathways and their contribution to cognitive function improvement and rescue from mitochondria-related abnormalities as treatment strategies for neurodegenerative diseases that often affect elderly individuals.

Targeting Glucose Metabolism: A Novel Therapeutic Approach for Parkinson's Disease

Glucose metabolism is essential for the maintenance and function of the central nervous system. Although the brain constitutes only 2% of the body weight, it consumes approximately 20% of the body's total energy, predominantly derived from glucose. This high energy demand of the brain underscores its reliance on glucose to fuel various functions, including neuronal activity, synaptic transmission, and the maintenance of ion gradients necessary for nerve impulse transmission. Increasing evidence shows that many neurodegenerative diseases, including Parkinson's disease (PD), are associated with abnormalities in glucose metabolism. PD is characterized by the progressive loss of dopaminergic neurons in the substantia nigra, accompanied by the accumulation of α-synuclein protein aggregates. These pathological features are exacerbated by mitochondrial dysfunction, oxidative stress, and neuroinflammation, all of which are influenced by glucose metabolism disruptions. Emerging evidence suggests that targeting glucose metabolism could offer therapeutic benefits for PD. Several antidiabetic drugs have shown promise in animal models and clinical trials for mitigating the symptoms and progression of PD. This review explores the current understanding of the association between PD and glucose metabolism, emphasizing the potential of antidiabetic medications as a novel therapeutic approach. By improving glucose uptake and utilization, enhancing mitochondrial function, and reducing neuroinflammation, these drugs could address key pathophysiological mechanisms in PD, offering hope for more effective management of this debilitating disease.

Isolation of Lessertiosides A and B and Other Metabolites from Lessertia frutescens and Their Neuroprotection Activity

Lessertia frutescens (synonym Sutherlandia frutescens) is an important South African medicinal plant used traditionally to treat different human pathologies and is considered an adaptogenic plant. This study sought to isolate compounds from the plant and determine their protective potentials using SH-SY5Y cells and MPP+ (1-methyl-4-phenylpyridinium) to mimic Parkinson's disease. The phytochemical analysis of a 70% aqueous methanolic extract of L. frutescens leaves resulted in the isolation and identification of 11 pure compounds (1-11), among which compounds 1 and 2 were identified as new metabolites. The new compounds were characterised using IR, UV, NMR, and HRESIMS and were given the trivial names lessertiosides A (1) and B (2). Additionally, the flavonoids 8-methoxyvestitol (7) and mucronulatol (8) were isolated for the first time from the plant. The biological actions show that the isolated compounds had negligible toxicity on SH-SY5Y cells and improved cell viability in the cells exposed to MPP+. Furthermore, as a mechanism of action, the compounds could sustain cellular ATP generation and prevent MPP+-induced apoptotic cell death. Our findings provide evidence for the neuroprotective properties of compounds isolated from L. frutescens in MPP+-induced neuronal damage for the first time and create an avenue for these compounds to be further investigated to elucidate their molecular targets.

Neuroprotective Role of Transchalcone in Parkinson's Disease through AMP-activated Protein Kinase-mediated Signaling Pathway

ABSTRACT

Parkinson's disease (PD) is a gradually worsening neurodegenerative condition marked by the deterioration of dopaminergic neurons, motor dysfunction, and mitochondrial dysfunction. Trans-chalcone, a natural flavonoid, has shown promise in various disease models because of its antioxidant and anti-inflammatory features. This study investigates the neuroprotective effects of transchalcone in a rat model of PD, focusing on its impact on the activation levels of AMP-activated protein kinase (AMPK) signaling pathway, sirtuin1 (SIRT1) and peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC1α) proteins, and mitochondrial-inflammatory responses. Male Sprague Dawley rats were allocated into five groups Control, Control plus transchalcone, PD, PD plus transchalcone, PD plus compound-C, and PD plus Compound-C and trans-chalcone. PD was induced using intranigral 6-hydroxydopamine injection. Trans-chalcone (100 μg/kg) and compound-C (20 mg/kg) were intraperitoneally administered daily for 4 weeks in PD rats. Motor function was assessed using rota-rod and grid tests. Striatal dopamine and cytokines (interleukin 1-beta [IL-1 β], IL-10) and p65-nuclear factor kappa-B (NF-κB) levels were measured with enzyme-linked immunosorbent assay. Mitochondrial function was evaluated by fluorometric techniques. The expression of phosphorylated AMPK, PGC-1α, and SIRT1 was analyzed by Western blotting. Trans-chalcone treatment significantly improved motor function, evidenced by increased latency to fall in the rota-rod test and recovered traversal time in the grid test. It also restored dopamine levels, enhanced mitochondrial function (reduced reactive oxygen species levels, increased membrane potential, and adenosine triphosphate production), normalized cytokines (IL-1 β, IL-10) and p65-NF-κB, and upregulated the proteins expression in rats with PD. Inhibition of AMPK activity with compound-C suppressed the neuroprotective impacts of trans-chalcone, highlighting the contribution of AMPK signaling pathway in its mechanism of action. Neuroprotective and mitoprotective impacts of trans-chalcone were mostly mediated through the activation of AMPK-SIRT1-PGC1α pathway. These results indicate that trans-chalcone could be a promising therapeutic agent for PD, warranting further investigation to assess its efficacy and safety in human patients.

Mitophagy Upregulation Occurs Early in the Neurodegenerative Process Mediated by α-Synuclein

Parkinson's disease (PD) is a progressive neurogenerative movement disorder characterized by dopaminergic cell death within the substantia nigra pars compacta (SNpc) due to the aggregation-prone protein α-synuclein. Accumulation of α-synuclein is implicated in mitochondrial dysfunction and disruption of the autophagic turnover of mitochondria, or mitophagy, which is an essential quality control mechanism proposed to preserve mitochondrial fidelity in response to aging and stress. Yet, the precise relationship between α-synuclein accumulation, mitochondrial autophagy, and dopaminergic cell loss remains unresolved. Here, we determine the kinetics of α-synuclein overexpression and mitophagy using the pH-sensitive fluorescent mito-QC reporter. We find that overexpression of mutant A53T α-synuclein in either human SH-SY5Y cells or rat primary cortical neurons induces mitophagy. Moreover, the accumulation of mutant A53T α-synuclein in the SNpc of rats results in mitophagy dysregulation that precedes the onset of dopaminergic neurodegeneration. This study reveals a role for mutant A53T α-synuclein in inducing mitochondrial dysfunction, which may be an early event contributing to neurodegeneration.

Integrative Metabolome and Proteome Analysis of Cerebrospinal Fluid in Parkinson's Disease

Parkinson's disease (PD) is a common neurodegenerative disorder characterized by the loss of dopaminergic neurons in the substantia nigra. Recent studies have highlighted the significant role of cerebrospinal fluid (CSF) in reflecting pathophysiological PD brain conditions by analyzing the components of CSF. Based on the published literature, we created a single network with altered metabolites in the CSF of patients with PD. We analyzed biological functions related to the transmembrane of mitochondria, respiration of mitochondria, neurodegeneration, and PD using a bioinformatics tool. As the proteome reflects phenotypes, we collected proteome data based on published papers, and the biological function of the single network showed similarities with that of the metabolomic network. Then, we analyzed the single network of integrated metabolome and proteome. In silico predictions based on the single network with integrated metabolomics and proteomics showed that neurodegeneration and PD were predicted to be activated. In contrast, mitochondrial transmembrane activity and respiration were predicted to be suppressed in the CSF of patients with PD. This review underscores the importance of integrated omics analyses in deciphering PD's complex biochemical networks underlying neurodegeneration.

Mitochondrial Dysfunction as a Potential Mechanism Mediating Cardiac Comorbidities in Parkinson's Disease

Individuals diagnosed with Parkinson's disease (PD) often exhibit heightened susceptibility to cardiac dysfunction, reflecting a complex interaction between these conditions. The involvement of mitochondrial dysfunction in the development and progression of cardiac dysfunction and PD suggests a plausible commonality in some aspects of their molecular pathogenesis, potentially contributing to the prevalence of cardiac issues in PD. Mitochondria, crucial organelles responsible for energy production and cellular regulation, play important roles in tissues with high energetic demands, such as neurons and cardiac cells. Mitochondrial dysfunction can occur in different and non-mutually exclusive ways; however, some mechanisms include alterations in mitochondrial dynamics, compromised bioenergetics, biogenesis deficits, oxidative stress, impaired mitophagy, and disrupted calcium balance. It is plausible that these factors contribute to the increased prevalence of cardiac dysfunction in PD, suggesting mitochondrial health as a potential target for therapeutic intervention. This review provides an overview of the physiological mechanisms underlying mitochondrial quality control systems. It summarises the diverse roles of mitochondria in brain and heart function, highlighting shared pathways potentially exhibiting dysfunction and driving cardiac comorbidities in PD. By highlighting strategies to mitigate dysfunction associated with mitochondrial impairment in cardiac and neural tissues, our review aims to provide new perspectives on therapeutic approaches.

Novel neuroprotective 5,6-dihydropyrido[2',1':2,3]imidazo[4,5-c]quinoline derivatives acting through cholinesterase inhibition and CB2 signaling modulation

A novel group of 5,6-dihydropyrido [2',1':2,3]imidazo [4,5-c]quinolines was prepared via a microwave assisted one-pot telescopic approach. The synthetic sequence involves the formation of an amine precursor of imidazo [1,2-a]pyridine via condensation and reduction under microwave irradiation. Subsequently, the Pictet-Spengler cyclisation reaction occurs with ketones (cyclic or acyclic) to obtain substituted 5,6-dihydropyrido [2',1':2,3]imidazo [4,5-c]quinolines in excellent yields. The compounds were tested as neuroprotective agents. Observed protection of neuron-like cells, SH-SY5Y differentiated with ATRA, in Parkinson's and Huntington's disease models inspired further mechanistic studies of protective activity against damage induced by 1-methyl-4-phenylpyridinium (MPP+), a compound causing Parkinson's disease. The novel compounds exhibit similar or higher potency than ebselen, an established drug with antioxidant activity, in the cells against MPP + -induced total cellular superoxide production and cell death. However, they exhibit a significantly higher capacity to reduce mitochondrial superoxide and preserve mitochondrial membrane potential. We also observed marked differences between a selected derivative and ebselen in terms of normalizing MPP + -induced phosphorylation of Akt and ERK1/2. The cytoprotective activity was abrogated when signaling through cannabinoid receptor CB2 was blocked. The compounds also inhibit both acetylcholine and butyrylcholine esterases. Overall the data show that novel 5,6-dihydropyrido [2',1':2,3]imidazo [4,5-c]quinoline have a broad cytoprotective activity which is mediated by several mechanisms including mitoprotection.

The Interplay of Mitochondrial Bioenergetics and Dopamine Agonists as an Effective Disease-Modifying Therapy for Parkinson's Disease

Parkinson's disease (PD) is a progressive neurological ailment with a slower rate of advancement that is more common in older adults. The biggest risk factor for PD is getting older, and those over 60 have an exponentially higher incidence of this condition. The failure of the mitochondrial electron chain, changes in the dynamics of the mitochondria, and abnormalities in calcium and ion homeostasis are all symptoms of Parkinson's disease (PD). Increased mitochondrial reactive oxygen species (mROS) and an energy deficit are linked to these alterations. Levodopa (L-DOPA) is a medication that is typically used to treat most PD patients, but because of its negative effects, additional medications have been created utilizing L-DOPA as the parent molecule. Ergot and non-ergot derivatives make up most PD medications. PD is successfully managed with the use of dopamine agonists (DA). To get around the motor issues produced by L-DOPA, these dopamine derivatives can directly excite DA receptors in the postsynaptic membrane. In the past 10 years, two non-ergoline DA with strong binding properties for the dopamine D2 receptor (D2R) and a preference for the dopamine D3 receptor (D3R) subtype, ropinirole, and pramipexole (PPx) have been developed for the treatment of PD. This review covers the most recent research on the efficacy and safety of non-ergot drugs like ropinirole and PPx as supplementary therapy to DOPA for the treatment of PD.

Ergothioneine and mitochondria: An important protective mechanism?

Mitochondrial dysfunction is implicated in a wide range of human disorders including many neurodegenerative and cardiovascular diseases, metabolic diseases, cancers, and respiratory disorders. Studies have suggested the potential of l-ergothioneine (ET), a unique dietary thione, to prevent mitochondrial damage and improve disease outcome. Despite this, no studies have definitively demonstrated uptake of ET into mitochondria. Moreover, the expression of the known ET transporter, OCTN1, on the mitochondria remains controversial. In this study, we utilise mass spectrometry to demonstrate direct ET uptake in isolated mitochondria as well as its presence in mitochondria isolated from ET-treated cells and animals. Mitochondria isolated from OCTN1 knockout mice tissues, have impaired but still detectable ET uptake, raising the possibility of alternative transporter(s) which may facilitate ET uptake into the mitochondria. Our data confirm that ET can enter mitochondria, providing a basis for further work on ET in the prevention of mitochondrial dysfunction in human disease.

Oxidative stress modulating nanomaterials and their biochemical roles in nanomedicine

Many pathological conditions are predominantly associated with oxidative stress, arising from reactive oxygen species (ROS); therefore, the modulation of redox activities has been a key strategy to restore normal tissue functions. Current approaches involve establishing a favorable cellular redox environment through the administration of therapeutic drugs and redox-active nanomaterials (RANs). In particular, RANs not only provide a stable and reliable means of therapeutic delivery but also possess the capacity to finely tune various interconnected components, including radicals, enzymes, proteins, transcription factors, and metabolites. Here, we discuss the roles that engineered RANs play in a spectrum of pathological conditions, such as cancer, neurodegenerative diseases, infections, and inflammation. We visualize the dual functions of RANs as both generator and scavenger of ROS, emphasizing their profound impact on diverse cellular functions. The focus of this review is solely on inorganic redox-active nanomaterials (inorganic RANs). Additionally, we deliberate on the challenges associated with current RANs-based approaches and propose potential research directions for their future clinical translation.

Temporal Dynamics of Oxidative Stress and Inflammation in Bronchopulmonary Dysplasia

Bronchopulmonary dysplasia (BPD) is the most common lung complication of prematurity. Despite extensive research, our understanding of its pathophysiology remains limited, as reflected by the stable prevalence of BPD. Prematurity is the primary risk factor for BPD, with oxidative stress (OS) and inflammation playing significant roles and being closely linked to premature birth. Understanding the interplay and temporal relationship between OS and inflammation is crucial for developing new treatments for BPD. Animal studies suggest that OS and inflammation can exacerbate each other. Clinical trials focusing solely on antioxidants or anti-inflammatory therapies have been unsuccessful. In contrast, vitamin A and caffeine, with antioxidant and anti-inflammatory properties, have shown some efficacy, reducing BPD by about 10%. However, more than one-third of very preterm infants still suffer from BPD. New therapeutic agents are needed. A novel tripeptide, N-acetyl-lysyltyrosylcysteine amide (KYC), is a reversible myeloperoxidase inhibitor and a systems pharmacology agent. It reduces BPD severity by inhibiting MPO, enhancing antioxidative proteins, and alleviating endoplasmic reticulum stress and cellular senescence in a hyperoxia rat model. KYC represents a promising new approach to BPD treatment.

Primary cilia in Parkinson's disease: summative roles in signaling pathways, genes, defective mitochondrial function, and substantia nigra dopaminergic neurons

Primary cilia (PC) are microtubules-based, independent antennal-like sensory organelles, that are seen in most vertebrate cells of different types, including astrocytes and neurons. They send signals to cells to control many physiological and cellular processes by detecting changes in the extracellular environment. Parkinson's disease (PD), a neurodegenerative disease that progresses over time, is primarily caused by a gradual degradation of the dopaminergic pathway in the striatum nigra, which results in a large loss of neurons in the substantia nigra compact (SNpc) and a depletion of dopamine (DA). PD samples have abnormalities in the structure and function of PC. The alterations contribute to the cause, development, and recovery of PD via influencing signaling pathways (SHH, Wnt, Notch-1, α-syn, and TGFβ), genes (MYH10 and LRRK2), defective mitochondrial function, and substantia nigra dopaminergic neurons. Thus, restoring the normal structure and physiological function of PC and neurons in the brain are effective treatment for PD. This review summarizes the function of PC in neurodegenerative diseases and explores the pathological mechanisms caused by PC alterations in PD, in order to provide references and ideas for future research.

Neuroprotective effects of L-Dopa-modified zinc oxide nanoparticles on the rat model of 6-OHDA-ınduced Parkinson's disease

Parkinson's disease (PD) is a chronic neurodegenerative case. As the disease progresses, the response time to doses of levodopa (L-Dopa) becomes shorter and the effects of the drug are severely limited by some undesirable side effects such as the 'on-off' phenomenon. In several diseases, including Parkinson's, nanoparticles can deliver antioxidant compounds that reduce oxidative stress. This study evaluates and compares the neuroprotective effects of L-Dopa-modified zinc nanoparticles (ZnNPs) in the 6-hydroxydopamine (6-OHDA)-induced PD rat model. For this purpose, the synthesis of NPs was carried out. Scanning electron microscopy, X-ray diffraction and Fourier transform infrared spectrophotometer were used for characterization. The rats were randomized into 9 experimental groups: control, lesion group (6-OHDA), 6-OHDA + 5 mg/kg L-Dopa, 6-OHDA + 10 mg/kg L-Dopa, 6-OHDA + 20 mg/kg L-Dopa, 6-OHDA + 20 mg/kg ZnNPs, 6-OHDA + 40 mg/kg ZnNPs, 6-OHDA + 30 mg/kg ZnNPs + L-Dopa, and 6-OHDA + 60 mg/kg ZnNPs + L-Dopa. Behavioral tests were performed on all groups 14 days after treatment. Phosphatase and tensin homolog, Excitatory amino acid transporter 1/2, and Glutamine synthetase gene analyses were performed on brain samples taken immediately after the tests. In addition, histological and immunohistochemical methods were used to determine the general structure and properties of the tissues. We obtained important findings that L-Dopa-modified ZnNPs increased the activity of glutamate transporters. Our experiment showed that glutamate increases neuronal cell vitality and improves behavioral performance. Therefore, L-Dopa-modified ZnNPs can be used to prevent neurotoxicity. According to what we found, results show that L-Dopa-modified ZnNPs will lend to the effective avoidance and therapy of PD.

Construct, Face, and Predictive Validity of Parkinson's Disease Rodent Models

Parkinson's disease (PD) is the second most common neurodegenerative disease globally. Current drugs only alleviate symptoms without halting disease progression, making rodent models essential for researching new therapies and understanding the disease better. However, selecting the right model is challenging due to the numerous models and protocols available. Key factors in model selection include construct, face, and predictive validity. Construct validity ensures the model replicates pathological changes seen in human PD, focusing on dopaminergic neurodegeneration and a-synuclein aggregation. Face validity ensures the model's symptoms mirror those in humans, primarily reproducing motor and non-motor symptoms. Predictive validity assesses if treatment responses in animals will reflect those in humans, typically involving classical pharmacotherapies and surgical procedures. This review highlights the primary characteristics of PD and how these characteristics are validated experimentally according to the three criteria. Additionally, it serves as a valuable tool for researchers in selecting the most appropriate animal model based on established validation criteria.

Excitotoxicity, Oxytosis/Ferroptosis, and Neurodegeneration: Emerging Insights into Mitochondrial Mechanisms

Mitochondrial dysfunction plays a pivotal role in the development of age-related diseases, particularly neurodegenerative disorders. The etiology of mitochondrial dysfunction involves a multitude of factors that remain elusive. This review centers on elucidating the role(s) of excitotoxicity, oxytosis/ferroptosis and neurodegeneration within the context of mitochondrial bioenergetics, biogenesis, mitophagy and oxidative stress and explores their intricate interplay in the pathogenesis of neurodegenerative diseases. The effective coordination of mitochondrial turnover processes, notably mitophagy and biogenesis, is assumed to be critically important for cellular resilience and longevity. However, the age-associated decrease in mitophagy impedes the elimination of dysfunctional mitochondria, consequently impairing mitochondrial biogenesis. This deleterious cascade results in the accumulation of damaged mitochondria and deterioration of cellular functions. Both excitotoxicity and oxytosis/ferroptosis have been demonstrated to contribute significantly to the pathophysiology of neurodegenerative diseases, including Alzheimer's disease (AD), Parkinson's disease (PD), Huntington's Disease (HD), Amyotrophic Lateral Sclerosis (ALS) and Multiple Sclerosis (MS). Excitotoxicity, characterized by excessive glutamate signaling, initiates a cascade of events involving calcium dysregulation, energy depletion, and oxidative stress and is intricately linked to mitochondrial dysfunction. Furthermore, emerging concepts surrounding oxytosis/ferroptosis underscore the importance of iron-dependent lipid peroxidation and mitochondrial engagement in the pathogenesis of neurodegeneration. This review not only discusses the individual contributions of excitotoxicity and ferroptosis but also emphasizes their convergence with mitochondrial dysfunction, a key driver of neurodegenerative diseases. Understanding the intricate crosstalk between excitotoxicity, oxytosis/ferroptosis, and mitochondrial dysfunction holds potential to pave the way for mitochondrion-targeted therapeutic strategies. Such strategies, with a focus on bioenergetics, biogenesis, mitophagy, and oxidative stress, emerge as promising avenues for therapeutic intervention.

Artificial intelligence in Parkinson's disease: Early detection and diagnostic advancements

Parkinson's disease (PD) is the second most common neurodegenerative disorder, globally affecting men and women at an exponentially growing rate, with currently no cure. Disease progression starts when dopaminergic neurons begin to die. In PD, the loss of neurotransmitter, dopamine is responsible for the overall communication of neural cells throughout the body. Clinical symptoms of PD are slowness of movement, involuntary muscular contractions, speech & writing changes, lessened automatic movement, and chronic tremors in the body. PD occurs in both familial and sporadic forms and modifiable and non-modifiable risk factors and socioeconomic conditions cause PD. Early detectable diagnostics and treatments have been developed in the last several decades. However, we still do not have precise early detectable biomarkers and therapeutic agents/drugs that prevent and/or delay the disease process. Recently, artificial intelligence (AI) science and machine learning tools have been promising in identifying early detectable markers with a greater rate of accuracy compared to past forms of treatment and diagnostic processes. Artificial intelligence refers to the intelligence exhibited by machines or software, distinct from the intelligence observed in humans that is based on neural networks in a form and can be used to diagnose the longevity and disease severity of disease. The term Machine Learning or Neural Networks is a blanket term used to identify an emerging technology that is created to work in the way of a "human brain" using many intertwined neurons to achieve the same level of raw intelligence as that of a brain. These processes have been used for neurodegenerative diseases such as Parkinson's disease and Alzheimer's disease, to assess the severity of the patient's condition. In the current article, we discuss the prevalence and incidence of PD, and currently available diagnostic biomarkers and therapeutic strategies. We also highlighted currently available artificial intelligence science and machine learning tools and their applications to detect disease and develop therapeutic interventions.

Mitochondrial plasticity and synaptic plasticity crosstalk; in health and Alzheimer's disease

Synaptic plasticity is believed to underlie the cellular and molecular basis of memory formation. Mitochondria are one of the main organelles involved in metabolism and energy maintenance as plastic organelles that change morphologically and functionally in response to cellular needs and regulate synaptic function and plasticity through multiple mechanisms, including ATP generation, calcium homeostasis, and biogenesis. An increased neuronal activity enhances synaptic efficiency, during which mitochondria's spatial distribution and morphology change significantly. These organelles build up in the pre-and postsynaptic zones to produce ATP, which is necessary for several synaptic processes like neurotransmitter release and recycling. Mitochondria also regulate calcium homeostasis by buffering intracellular calcium, which ensures proper synaptic activity. Furthermore, mitochondria in the presynaptic terminal have distinct morphological properties compared to dendritic or postsynaptic mitochondria. This specialization enables precise control of synaptic activity and plasticity. Mitochondrial dysfunction has been linked to synaptic failure in many neurodegenerative disorders, like Alzheimer's disease (AD). In AD, malfunctioning mitochondria cause delays in synaptic vesicle release and recycling, ionic gradient imbalances, and mostly synaptic failure. This review emphasizes mitochondrial plasticity's contribution to synaptic function. It also explores the profound effect of mitochondrial malfunction on neurodegenerative disorders, focusing on AD, and provides an overview of how they sustain cellular health under normal conditions and how their malfunction contributes to neurodegenerative diseases, highlighting their potential as a therapeutic target for such conditions.

Circadian rhythm alterations affecting the pathology of neurodegenerative diseases

The circadian rhythm is a nearly 24-h oscillation found in various physiological processes in the human brain and body that is regulated by environmental and genetic factors. It is responsible for maintaining body homeostasis and it is critical for essential functions, such as metabolic regulation and memory consolidation. Dysregulation in the circadian rhythm can negatively impact human health, resulting in cardiovascular and metabolic diseases, psychiatric disorders, and premature death. Emerging evidence points to a relationship between the dysregulation circadian rhythm and neurodegenerative diseases, suggesting that the alterations in circadian function might play crucial roles in the pathogenesis and progression of neurodegenerative diseases. Better understanding this association is of paramount importance to expand the knowledge on the pathophysiology of neurodegenerative diseases, as well as, to provide potential targets for the development of new interventions based on the dysregulation of circadian rhythm. Here we review the latest findings on dysregulation of circadian rhythm alterations in Parkinson's disease, Alzheimer's disease, Huntington's disease, amyotrophic lateral sclerosis, multiple sclerosis, spinocerebellar ataxia and multiple-system atrophy, focusing on research published in the last 3 years.

Mitochondrial protective potential of fucoxanthin in brain disorders

Mitochondrial dysfunction is a common feature of brain disorders. Mitochondria play a central role in oxidative phosphorylation; thus changes in energy metabolism in the brain have been reported in conditions such as Alzheimer's disease, Parkinson's disease, and stroke. In addition, mitochondria regulate cellular responses associated with neuronal damage such as the production of reactive oxygen species (ROS), opening of the mitochondrial permeability transition pore (mPTP), and apoptosis. Therefore, interventions that aim to protect mitochondria may be effective against brain disorders. Fucoxanthin is a marine carotenoid that has recently gained recognition for its neuroprotective properties. However, the cellular mechanisms of fucoxanthin in brain disorders, particularly its role in mitochondrial function, have not been thoroughly discussed. This review summarises the current literature on the effects of fucoxanthin on oxidative stress, neuroinflammation, and apoptosis using in vitro and in vivo models of brain disorders. We further present the potential mechanisms by which fucoxanthin protects mitochondria, with the objective of developing dietary interventions for a spectrum of brain disorders. Although the studies reviewed are predominantly preclinical studies, they provide important insights into understanding the cellular and molecular functions of fucoxanthin in the brain. Future studies investigating the mechanisms of action and the molecular targets of fucoxanthin are warranted to develop translational approaches to brain disorders.

Coffee and Parkinson's disease

Parkinson's disease (PD) is a prevalent neurodegenerative disease marked by dopaminergic neuronal loss and misfolded alpha-synuclein (α-syn) accumulation, which results in both motor and cognitive symptoms. Its occurrence grows with age, with a larger prevalence among males. Despite substantial study, effective medicines to reduce or stop the progression of diseases remain elusive. Interest has grown in examining dietary components, such as caffeine present in coffee, for potential medicinal effects. Epidemiological studies imply a lower incidence of PD with coffee drinking, attributable to caffeine's neuroprotective abilities. Beyond caffeine, coffee constituent like chlorogenic acid and cafestol have anti-Parkinsonian benefits. Moreover, coffee use has been related with variations in gut microbiota composition, which may reduce intestinal inflammation and prevent protein misfolding in enteric nerves, perhaps through the microbiota-gut-brain axis. This review gives a summary of the neuroprotective effects of coffee, investigating both its motor and non-motor advantages in individuals with PD as well as in experimental models of PD. We reviewed some bioactive constituents of coffee, their respective interactions with misfolded α-syn accumulation, and its emerging mechanisms associated to the gut microbiome.

The mechanistic view of non-coding RNAs as a regulator of inflammatory pathogenesis of Parkinson's disease

Parkinson's disease (PD) is a neurodegenerative disorder characterized by the progressive loss of dopaminergic neurons in the substantia nigra pars compacta, leading to motor and non-motor symptoms. Emerging evidence suggests that inflammation plays a crucial role in the pathogenesis of PD, with the NLRP3 inflammasome implicated as a key mediator. Nfon-coding RNAs (ncRNAs), including microRNAs (miRNAs) and long non-coding RNAs (lncRNAs), have recently garnered attention for their regulatory roles in various biological processes, including inflammation. This review aims to provide a mechanistic insight into how ncRNAs function as regulators of inflammatory pathways in PD, with a specific focus on the NLRP3 inflammasome. We discuss the dysregulation of miRNAs and lncRNAs in PD pathogenesis and their impact on neuroinflammation through modulation of NLRP3 activation, cytokine production, and microglial activation. Additionally, we explore the crosstalk between ncRNAs, alpha-synuclein pathology, and mitochondrial dysfunction, further elucidating the intricate network underlying PD-associated inflammation. Understanding the mechanistic roles of ncRNAs in regulating inflammatory pathways may offer novel therapeutic targets for the treatment of PD and provide insights into the broader implications of ncRNA-mediated regulation in neuroinflammatory diseases.

Systematic identification of structure-specific protein-protein interactions

The physical interactome of a protein can be altered upon perturbation, modulating cell physiology and contributing to disease. Identifying interactome differences of normal and disease states of proteins could help understand disease mechanisms, but current methods do not pinpoint structure-specific PPIs and interaction interfaces proteome-wide. We used limited proteolysis-mass spectrometry (LiP-MS) to screen for structure-specific PPIs by probing for protease susceptibility changes of proteins in cellular extracts upon treatment with specific structural states of a protein. We first demonstrated that LiP-MS detects well-characterized PPIs, including antibody-target protein interactions and interactions with membrane proteins, and that it pinpoints interfaces, including epitopes. We then applied the approach to study conformation-specific interactors of the Parkinson's disease hallmark protein alpha-synuclein (aSyn). We identified known interactors of aSyn monomer and amyloid fibrils and provide a resource of novel putative conformation-specific aSyn interactors for validation in further studies. We also used our approach on GDP- and GTP-bound forms of two Rab GTPases, showing detection of differential candidate interactors of conformationally similar proteins. This approach is applicable to screen for structure-specific interactomes of any protein, including posttranslationally modified and unmodified, or metabolite-bound and unbound protein states.

Enhanced translocation of TRIM32 to mitochondria sensitizes dopaminergic neuronal cells to apoptosis during stress conditions in Parkinson's disease

Parkinson's disease (PD) is a chronic neurodegenerative disease characterized by progressive loss of dopamine-producing neurons from the substantia nigra region of the brain. Mitochondrial dysfunction is one of the major causes of oxidative stress and neuronal cell death in PD. E3 ubiquitin ligases such as Parkin (PRKN) modulate mitochondrial quality control in PD; however, the role of other E3 ligases associated with mitochondria in the regulation of neuronal cell death in PD has not been explored. The current study investigated the role of TRIM32, RING E3 ligase, in sensitization to oxidative stress-induced neuronal apoptosis. The expression of TRIM32 sensitizes SH-SY5Y dopaminergic cells to rotenone and 6-OHDA-induced neuronal death, whereas the knockdown increased cell viability under PD stress conditions. The turnover of TRIM32 is enhanced under PD stress conditions and is mediated by autophagy. TRIM32 translocation to mitochondria is enhanced under PD stress conditions and localizes on the outer mitochondrial membrane. TRIM32 decreases complex-I assembly and activity as well as mitochondrial reactive oxygen species (ROS) and ATP levels under PD stress. Deletion of the RING domain of TRIM32 enhanced complex I activity and rescued ROS levels and neuronal viability under PD stress conditions. TRIM32 decreases the level of XIAP, and co-expression of XIAP with TRIM32 rescued the PD stress-induced cell death and mitochondrial ROS level. In conclusion, turnover of TRIM32 increases during stress conditions and translocation to mitochondria is enhanced, regulating mitochondrial functions and neuronal apoptosis by modulating the level of XIAP in PD.

Safety, tolerability and toxicokinetics of the novel mitochondrial drug SUL-138 administered orally to rat and minipig

Noncommunicable Chronic Diseases (NCD) are a socioeconomic burden and considered one of the major health challenges for coming decades. Mitochondrial dysfunction has been implicated mechanistically in their pathophysiology. Therefore, targeting mitochondria holds great promise to improve clinical outcomes in NCDs. SUL-138, an orally bioavailable small molecule efficacious from 0.5 mg/kg, improves mitochondrial function during disease in several preclinical animal models. As preparation for a First-in-Human (FIH) trial, SUL-138 was investigated in 30-day GLP repeated dose toxicity studies in rat and minipig, selected based on their comparability with human metabolism, to determine toxicokinetics, potential toxicity and its reversibility. Rats were allocated to either vehicle, 27, 136 or 682 mg/kg SUL-138 dose groups and minipigs were allocated to either vehicle, 16, 82 or 409 mg/kg. Treatment occurred orally for 30 days followed by a recovery period of 14 days. During these studies clinical observations, toxicokinetic, clinical pathology, necropsy and histopathology evaluations were performed. There was significant systemic exposure to SUL-138 and toxicokinetics was characterized by a rapid absorption and elimination. In the rat, toxicokinetics was dose-proportional and AUC0-tlast ratios in both species indicated that SUL-138 does not accumulate in vivo. No treatment-related adverse effects were observed for dose levels up to 136 and 82 mg/kg/day in rat and minipig respectively. In conclusion, these preclinical studies demonstrate that SUL-138 is well tolerated after repeated administration in rat and minipig, with NOAELs of 136 and 82 mg/kg/day, respectively.

Autophagy-associated non-coding RNAs: Unraveling their impact on Parkinson's disease pathogenesis

BACKGROUND

Parkinson's disease (PD) is a degenerative neurological condition marked by the gradual loss of dopaminergic neurons in the substantia nigra pars compacta. The precise etiology of PD remains unclear, but emerging evidence suggests a significant role for disrupted autophagy-a crucial cellular process for maintaining protein and organelle integrity.

METHODS

This review focuses on the role of non-coding RNAs (ncRNAs) in modulating autophagy in PD. We conducted a comprehensive review of recent studies to explore how ncRNAs influence autophagy and contribute to PD pathophysiology. Special attention was given to the examination of ncRNAs' regulatory impacts in various PD models and patient samples.

RESULTS

Findings reveal that ncRNAs are pivotal in regulating key processes associated with PD progression, including autophagy, α-synuclein aggregation, mitochondrial dysfunction, and neuroinflammation. Dysregulation of specific ncRNAs appears to be closely linked to these pathogenic processes.

CONCLUSION

ncRNAs hold significant therapeutic potential for addressing autophagy-related mechanisms in PD. The review highlights innovative therapeutic strategies targeting autophagy-related ncRNAs and discusses the challenges and prospective directions for developing ncRNA-based therapies in clinical practice. The insights from this study underline the importance of ncRNAs in the molecular landscape of PD and their potential in novel treatment approaches.

Mitochondrial Dysfunction and Metabolic Reprogramming in Obesity and Asthma

Mitochondrial dysfunction and metabolic reprogramming have been extensively studied in many disorders ranging from cardiovascular to neurodegenerative disease. Obesity has previously been associated with mitochondrial fragmentation, dysregulated glycolysis, and oxidative phosphorylation, as well as increased reactive oxygen species production. Current treatments focus on reducing cellular stress to restore homeostasis through the use of antioxidants or alterations of mitochondrial dynamics. This review focuses on the role of mitochondrial dysfunction in obesity particularly for those suffering from asthma and examines mitochondrial transfer from mesenchymal stem cells to restore function as a potential therapy. Mitochondrial targeted therapy to restore healthy metabolism may provide a unique approach to alleviate dysregulation in individuals with this unique endotype.

Autophagy and UPS pathway contribute to nicotine-induced protection effect in Parkinson's disease

The gradual nature of age-related neurodegeneration causes Parkinson's disease (PD) and impairs movement, memory, intellectual ability, and social interaction. One of the most prevalent neurodegenerative conditions affecting the central nervous system (CNS) among the elderly is PD. PD affects both motor and cognitive functions. Degeneration of dopaminergic (DA) neurons and buildup of the protein α-synuclein (α-Syn) in the substantia nigra pars compacta (SNpc) are two major causes of this disorder. Both UPS and ALS systems serve to eliminate α-Syn. Autophagy and UPS deficits, shortened life duration, and lipofuscin buildup accelerate PD. This sickness has no cure. Innovative therapies are halting PD progression. Bioactive phytochemicals may provide older individuals with a natural substitute to help delay the onset of neurodegenerative illnesses. This study examines whether nicotine helps transgenic C. elegans PD models. According to numerous studies, nicotine enhances synaptic plasticity and dopaminergic neuronal survival. Upgrades UPS pathways, increases autophagy, and decreases oxidative stress and mitochondrial dysfunction. At 100, 150, and 200 µM nicotine levels, worms showed reduced α-Syn aggregation, repaired DA neurotoxicity after 6-OHDA intoxication, increased lifetime, and reduced lipofuscin accumulation. Furthermore, nicotine triggered autophagy and UPS. We revealed nicotine's potential as a UPS and autophagy activator to prevent PD and other neurodegenerative diseases.

AMPK Signaling Pathway as a Potential Therapeutic Target for Parkinson's Disease

Parkinson's disease (PD) is the second most common neurodegenerative disease caused by the loss of dopaminergic neurons. Genetic factors, inflammatory responses, oxidative stress, metabolic disorders, cytotoxic factors, and mitochondrial dysfunction are all involved in neuronal death in neurodegenerative diseases. The risk of PD can be higher in aging individuals due to decreased mitochondrial function, energy metabolism, and AMP-activated protein kinase (AMPK) function. The potential of AMPK to regulate neurodegenerative disorders lies in its ability to enhance antioxidant capacity, reduce oxidative stress, improve mitochondrial function, decrease mitophagy and macroautophagy, and inhibit inflammation. In addition, it has been shown that modulating the catalytic activity of AMPK can protect the nervous system. This article reviews the mechanisms by which AMPK activation can modulate PD.

Dopaminergic neuronal death via necroptosis in Parkinson's disease: A review of the literature

Parkinson's disease (PD) is a neurodegenerative disorder characterized by progressive dysfunction and loss of dopaminergic neurons of the substantia nigra pars compacta (SNc). Several pathways of programmed cell death are likely to play a role in dopaminergic neuron death, such as apoptosis, necrosis, pyroptosis and ferroptosis, as well as cell death associated with proteasomal and mitochondrial dysfunction. A better understanding of the molecular mechanisms underlying dopaminergic neuron death could inform the design of drugs that promote neuron survival. Necroptosis is a recently characterized regulated cell death mechanism that exhibits morphological features common to both apoptosis and necrosis. It requires activation of an intracellular pathway involving receptor-interacting protein 1 kinase (RIP1 kinase, RIPK1), receptor-interacting protein 3 kinase (RIP3 kinase, RIPK3) and mixed lineage kinase domain-like pseudokinase (MLKL). The potential involvement of this programmed cell death pathway in the pathogenesis of PD has been studied by analysing biomarkers for necroptosis, such as the levels and oligomerization of phosphorylated RIPK3 (pRIPK3) and phosphorylated MLKL (pMLKL), in several PD preclinical models and in PD human tissue. Although there is evidence that other types of cell death also have a role in DA neuron death, most studies support the hypothesis that this cell death mechanism is activated in PD tissues. Drugs that prevent or reduce necroptosis may provide neuroprotection for PD. In this review, we summarize the findings from these studies. We also discuss how manipulating necroptosis might open a novel therapeutic approach to reduce neuronal degeneration in PD.

Mitochondria Dysfunction and Neuroinflammation in Neurodegeneration: Who Comes First?

Neurodegenerative diseases (NDs) encompass an assorted array of disorders such as Alzheimer's disease, Parkinson's disease, and amyotrophic lateral sclerosis, each characterised by distinct clinical manifestations and underlying pathological mechanisms. While some cases have a genetic basis, many NDs occur sporadically. Despite their differences, these diseases commonly feature chronic neuroinflammation as a hallmark. Consensus has recently been reached on the possibility that mitochondria dysfunction and protein aggregation can mutually contribute to the activation of neuroinflammatory response and thus to the onset and progression of these disorders. In the present review, we discuss the contribution of mitochondria dysfunction and neuroinflammation to the aetiology and progression of NDs, highlighting the possibility that new potential therapeutic targets can be identified to tackle neurodegenerative processes and alleviate the progression of these pathologies.